Effect of Repeated Low-Level Red Light Versus 0.01% Topical Atropine on Myopia Progression: A Randomized Crossover-Controlled Trial.

The purpose of this study was to compare the efficacy of repeated low-level red light (RLRL) and 0.01% atropine in controlling the progression of myopia children. This randomized, single-blind, crossover-controlled trial recruited 91 myopic children aged 6 to 12 years. Participants were randomly allocated to the RLRL-atropine group (n = 46) and the atropine-RLRL group (n = 45), with intermediate washout for 1 month. Primary outcomes included changes in spherical equivalent refraction (SER) and axial length (AL), whereas the secondary outcomes included changes in subfoveal choroidal thickness (SFCT) and subfoveal choroidal vessel volume (SFCVV). The 13-month data analysis involved 45 (97.8%) and 42 (93.3%) children in the RLRL-atropine and the atropine-RLRL groups, respectively. RLRL was more effective than 0.01% atropine, with a mean difference in SER of 0.54 diopter (D; 0.24 ± 0.30 D vs. -0.29 ± 0.38 D, P < 0.001) and a mean difference in AL of 0.24 mm (-0.09 ± 0.14 mm vs. 0.15 ± 0.16 mm, P < 0.001) in period 1, whereas the mean differences in SER and AL were 0.55 D (0.22 ± 0.27 D vs. -0.33 ± 0.27 D, P < 0.001) and 0.22 mm (-0.06 ± 0.13 mm vs. 0.16 ± 0.11 mm, P < 0.001) in period 2, respectively. RLRL showed increased SFCT and SFCVV than 0.01% atropine (all P < 0.001). The change in SFCT from baseline to 3 months was the crucial predictor for the growth in AL at 6 months (P < 0.05). Compared to 0.01% atropine, RLRL demonstrated superior effectiveness in slowing myopic progression and axial elongation in myopia children. Changes in SFCT may predict the retarding effects of RLRL on axial elongation. RLRL is an effective alternative treatment for controlling myopia in schoolchildren.